Page is loading ...
01-1
Motronic, On Board
Diagnostic (OBD)
On Board Diagnostic (OBD), technical
data
Equipment
Data is transmitted between the control module
and the VAS5051 tester or VAG1551 Scan Tool
(ST) via operating mode "Rapid Data Transfer".
DTC memory is designed for permanent
memory and is therefore not dependent on
voltage supply.
Display of stored DTCs occurs after initiation of
display mode Page 01-15 .
DTC memory must be erased after malfunction
is repaired Page 01-15 .
Important:
Readiness code must be re-generated after
every time DTC memory is erased Page 01-
82 .
Pa
g
e 1 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-2
If the ECM recognizes malfunctions that lead to
a degradation of emissions values, it indicates
them by lighting the Malfunction Indicator Lamp
(exhaust warning lamp -K83-). Clarification of
this lamp Page 01-3 .
"E-Gas"-relevant malfunctions are also
indicated in the instrument cluster by the
warning lamp for Electronic Power Control
("EPC warning lamp").
Pa
g
e 2 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-3
Malfunction Indicator Lamp (MIL),
significance
If the ECM recognizes malfunctions that lead to a
degradation of emissions values, it indicates
them by lighting the Malfunction Indicator Lamp
for exhaust.
Installation position of exhaust MIL
Note:
The Malfunction Indicator Lamp (MIL) can blink or remain lit continuously.
DTC memory should be checked in both cases Page 01-15 .
Blinking: There is a malfunction that causes damage to the catalytic
converter in this driving condition (e.g. combustion misfire). In this
case, vehicle must only be driven at reduced power!
Continuously lit: There is a malfunction that causes increased
emissions. Check DTC memory for Motronic ECM and automatic
transmission (if installed).
If there are driveability problems or if there is a customer complaint
and the exhaust MIL is not lit, DTC memory must be checked. There
may be DTCs stored that do not cause the exhaust MIL to light up
immediately, but only if malfunction is recognized again after repeated
engine starts.
Pa
g
e 3 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-4
Malfunction Indicator Lamp (MIL),
checking
Special Tools and Equipment
VAG1594A
VAG1598/31
Pa
g
e 4 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-5
Function test of warning lamp
- Switch ignition on.
Warning lamp for On Board Diagnostic
(Malfunction Indicator Lamp -MIL-) must
light up
A - Warning lamp for On Board Diagnostic
(Malfunction Indicator Lamp -MIL-) does not
light up
- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24-17 .
- Bridge sockets 1 and 47 of test box.
- Switch ignition on.
Warning lamp must light up.
If warning lamp does not light up:
- Switch ignition off.
- Remove instrument cluster:
Pa
g
e 5 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
Repair Manual, Electrical Equipment, Repair
Group 90, Instrument cluster, removing and
installing
Pa
g
e 6 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-6
- Check the following wire connection for open
circuit and short circuit to B+:
Test box
VAG1598/31
Socket
Instrument cluster
Terminal
47 Electrical Wiring Diagrams,
Troubleshooting & Component
Locations binder
- Repair open circuit or short circuit if
necessary.
If wire connection is OK:
- Replace Engine Control Module (ECM) Page
24-21 .
Pa
g
e 7 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-7
B - Warning lamp for On Board Diagnostic
(Malfunction Indicator Lamp -MIL-) remains lit
constantly
- Check DTC memory of Engine Control Module
(ECM) Page 01-15 .
If no DTCs are stored:
- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24-17 .
- Remove instrument cluster:
Repair Manual, Electrical Equipment, Repair
Group 90, Instrument cluster, removing and
installing
- Check the following wire connection for short
circuit to Ground (GND):
Test box
VAG1598/31
Socket
Instrument cluster
Terminal
47 Electrical Wiring Diagrams,
Pa
g
e 8 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
Troubleshooting & Component
Locations binder
- Repair short circuit if necessary.
If wire connection is OK:
- Replace Engine Control Module (ECM) Page
24-21 .
Pa
g
e 9 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-8
Safety precautions
If special testing equipment is required during
road test, note the following:
WARNING!
Scan tools and testing devices must always
be secured on the rear seat and operated
from there by a second person.
If a scan tool or testing device were to be
operated from the passenger seat and there
were an accident involving activation of the
passenger-side airbag, the person seated
there could be seriously injured.
Pa
g
e 10 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-9
VAS 5051 vehicle diagnostic, testing
and information system orVAG1551
Scan Tool (ST), connecting and
selecting functions
Test requirements:
Fuses for engine electronics OK
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
Fuel Pump (FP) OK, checking Page 24-
49 .
Battery voltage at least 12.7 V
Ground (GND) connections at engine and
transmission OK
Procedure
Note:
- Connect VAS5051 tester to vehicle with VAS5051/1 diagnostic wire.
Alternately, VAG1551 Scan Tool (ST) can also be attached using
VAG1551/3B cable.
Pa
g
e 11 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
Data Link Connector (DLC) is located in front left knee bolster.
Pa
g
e 12 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-10
WARNING!
Observe safety precautions Page 01-8 .
Note:
The following description only explains
implementation of On Board Diagnostic using
VAG1551 Scan tool.
When using the VAS5051 tester, observe the
tester's instructions for use
V
.A.G - ON BOARD DIAGNOSTIC HELP
1 - Rapid data transfer 1)
2 - Blink code output 1
)
Indicated on display:
1)
Operating modes 1 and 2 are displayed alternately
Note:
If nothing appears in display:
- Perform troubleshooting procedure after "troubleshooting procedure leak
test":
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder
Depending on desired function Table "Selectable functions", page
Page 01-14 :
- Switch ignition on.
or
Pa
g
e 13 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
- Start engine.
Pa
g
e 14 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-11
- Press -Print- button to turn on Scan Tool (ST)
printer. Indicator lamp in button must light up.
- Press button 1 to select "Rapid data transfer"
operating mode 1.
Rapid data transfer HELP
Insert address word XX
When indicated on display:
Note:
The address word 00 initiates the automatic test sequence, i.e. it results in
a DTC check on all OBD capable systems in the vehicle via rapid data
transfer.
- Press buttons -0- and -1- to select "engine electronics" and press -Q-
button to confirm input.
3B0907551BA 2.8l V6/5V G 0003
Codin
g
07251 WSC 12345
VAG1551 Scan Tool (ST) display indicates control module identification,
e.g.:
Note:
Control module identification can be printed by pressing the PRINT key of
the VAG1551 scan tool.
Pa
g
e 15 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-12
Control module identification (example)
3B0907551
BA
part number; allocation
Parts Catalog
2.8 L
Engine displacement
V6/5V
Construction style of engine (V
engine, 6 cylinder, 5 valves)
"G" i.e. no
indication
Vehicle with or without cruise
control system
0003
Data version (software
version) of control module
Coding
07251
Control module coding
WSC 12345
Factory identification of
VAG1551, with which the last
coding was performed
-
Press button.
Rapid data transfer HELP
Select function XX
Indicated on display (function selection):
Pa
g
e 16 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-13
Notes:
It will be possible to display the control module
identification again after pressing buttons -0-
and -1- to select "Check Control Module
Versions" and confirming with the -Q- button.
Rapid data transfer HELP
Control module does not answer
When indicated on display:
Rapid data transfer HELP
K-wire not switchin
g
to Ground
- Perform troubleshooting procedure after "troubleshooting procedure leak
test":
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder
Rapid data transfer HELP
K-wire not switchin
g
to B+
Rapid data transfer HELP
Error in communication link
Pa
g
e 17 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-14
Selectable functions
VAS 5051 vehicle diagnostic, testing and information
system or VAG1551 Scan Tool (ST)
Ignition
on,
engine
off
Engine running
at idle
Vehicle in drive
mode
page
Address words
01 Engine electronics Yes Yes Yes Page
01-9
00 Automatic test sequence Yes Yes Yes Page
01-11
Functions
01 Check Control Module Versions Yes Yes Yes Page
01-13
02 Check DTC Memory No Yes Yes Page
01-15
03 Output Diagnostic Test Mode (DTM) Yes No No Page
01-56
04 Basic Setting Yes Yes Yes Page
01-66
05 Erase DTC Memory Yes Yes Yes Page
01-15
06 End Output Yes Yes Yes Page
01-17
07 Code Control Module Yes No No Page
01-71
Pa
g
e 18 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
08 Read Measuring Value Block Yes Yes Yes Page
01-74
Pa
g
e 19 of 19Motronic, On Board Dia
g
nostic
(
OBD
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.1
01-15
Check DTC Memory (function
02) and Erase DTC Memory
(function 05)
- Connect VAS5051 tester or VAG1551 scan tool
and select the control module for engine
electronics using "address word" 01 Page 01-
9 .
Engine must run at idle for this.
Note:
If engine doesn't start, crank engine using starter
for at least 5 seconds. Do not switch ignition off
afterward under any circumstance.
Rapid data transfer HELP
Select function XX
When indicated on display:
- Press buttons -0- and -2- to select "Check DTC memory" and press -Q-
button to confirm input.
No DTC reco
g
nized
When indicated on display:
or
-
Press button.
X DTC reco
g
nized
When indicated on display:
Pa
g
e 1 of 52Check DTC Memor
y
(
function 02
)
and Erase DTC Memor
y
(
function 05
)
11/23/2002htt
p
://127.0.0.1:8080/audi/servlet/Dis
p
la
y
?action=Goto&t
yp
e=re
p
air&id=AUDI.B5.FU05.01.2
/
